Device for effecting equal tensile stresses in two threads



M. PAABO Dec. 22, 1959 DEVICE FOR EFFECTING EQUAL TENSILE STRESSES IN TWO THREADS Filed April 9, 1957 DEVICE FOR EFFECTING EQUAL TENSILE STRESSES IN TWO THREADS Max Paabo, Norrkoping, Sweden Application April 9, 1957, Serial No. 651,673

1 Claim. (Cl. 139-54) In textile machines it is often necessary to plait or Wind two threads around each other and around other threads which are orientated substantially at right angles to the two first-mentioned threads.

This necessity exists for example in looms without shuttles. When weaving with such looms the fabric will obtain no particular selvedge. In order to prevent the outermost list yarns from gliding out it is a wellknown matter, with regard to such looms, to use an apparatus which warps the two outermost warp threads at the two lists of the loom around each other and round the weft yarn so that binding of the list takes place. The warp threads used for this purpose are not stored on the warp beam but are delivered by particular bobbins which make part of the above-mentioned apparatus. The latter is mounted above the shaft mechanism of the loom and consists substantially of a preferably discshaped member revolving round a central axis, the said disc-shaped member carrying bobbins for the two threads, said threads being fed from the disc-shaped member at their respective feeding points which are located substantially diametrically opposite each other, whereafter the threads continue separately in a plane that is substantially perpendicular to the axis of rotation of the disc-shaped member to a delivery point of thread meeting, where, as a result of the rotary relative motion of the feeding points, the threads are interlaced and thereby bind further threads between them, which are inserted therebetween in pace with the rotary motion, preferably in a direction parallel with the axis of rotation.

The main object of the invention is to provide a device by means of which the tensile stress of two threads used in the above described manner can be equalized.

A particular object of the invention is to provide a device which is adapted to be used in such a case when the threads participating in the plaiting operation shall form a selvedge of a fabric manufactured by means of a loom without shuttle.

According to the characteristic of the invention this i has been accomplished by means of a stationary, guide bar member orientated along a diameter of the said disc member and somewhat spaced therefrom said guide bar member being substantially at right angles to the central plane normal to said disc and containing the axis of rotation of the disc member and the delivery point of the threads, the said guide bar member being adapted, when each thread feeding point is located between the guide bar member and the delivery point of the threads, to form of the appurtenant piece of thread a V-shaped loop for the purpose of keeping the lengths of the portions of the two threads located between the respective feeding points and their point of delivery substantially equal, in each position of rotation of the disc member,

2,918,092 Patented Dec. 22,

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independently of the-changes of the shortest distance between each feeding point and-the meeting point of the threads, which are due to the rotary motion.

An embodiment of theinvention will now be described with reference to the accompanying drawings and in respect of a loom without shuttle.

Fig. 1 shows an end view of the subject of the invention, some parts being omitted.

Fig. 2 shows a section along the line II-II in Fig. 1.

Fig. 3 shows partly an end view of the kind shown in Fig. l, the disc member being in another position of rotation, and partly a diagrammatical perspective view, which illustrates the operation of plaiting.

In order to make the drawings more surveyable only the members for one of the two threads within the apparatus itself that is, behind the end plate of the apparatus lying in the plane of the paper, have been shown in all the figures. It is understood, however, that similar members are provided for the other thread.

Referring now to the drawing, 1 designates the discshaped member rotating round a central shaft 2, the thread feeding means being provided at the back of the said member. The said thread feeding means may for each thread consist of a bobbin 3, a thread brake 4-, a guide pin 5 and a helical spring 6 rigidly secured at its one end and provided with a loop 7 at its free end. From the bobbin 3 the thread 8 passes the brake 4, the guide pin 5, the loop '7 and continues through a feed opening 9 in the disc 1. The other thread 10 runs in the same manner and leaves the device through the feed opening 11. All the details hitherto mentioned which participate in the rotary motion round the shaft 2, are preferably surrounded by a stationary housing 12 functioning as dust protection and provided with a lid 13.

After having left the disc member 1 the two threads 8 and 10 meet at a delivery point which, according to this embodiment is located, at the border of the fabric (Fig. 3), where the list threads are interlaced and thereby bind the weft threads 14 between them. Reference numeral 15 designates the normal warp threads. If the disc rotates in the direction indicated by the arrows from the position shown in Fig. l to the position shown in Fig. 3, the opening 11 will approach the point of meeting of the threads while the opening 9 will move away from the said point. In order to prevent the thread 10 from slackening a guide bar member 16 is provided some distance in front of the disc 1, which member 16 forms a V-shaped loop of the thread during this phase of the motion.

Due to the fact that in each position of rotation of the disc 1, the two feeding openings are always located at approximately the same distance from the guide bar 16, the latter together with the thread stretching springs 6 will effect that the lengths of the portions of the two threads between the respective feeding openings 9 and 11 and the points of meeting are constantly kept substantially equal, whereby the threads will always be subjected to equal tensile stresses, so that the weft threads can be easily inserted between the said threads and be interlaced therewith.

What I claim is:

Warp thread feeding and tensioning means for looms comprising a housing, a disk rotatably mounted in said housing, a pair of thread bobbins rotatably mounted on one side of said disk, said disk having a pair of openings diametrically arranged therein, the threads from said bobbins passing respectively through separate thread braking and spring tensioning means mounted on said disk and respectively through said openings to the other side of said disk, and means for guiding said threads from said openings to a delivery point laterally spaced from the periphery of said other side of said disk comprising a guide bar secured to said housing, said guide bar being parallel to and spaced from said other side of said disk, said guide bar being diametrically arranged with respect to said disk and having a length at least-as-g'rea't as the diameter of said disk, said guide bar being substantially normal to a central plane normal to said disk and passing through the axis of rotation of said disk and said delivery point whereby "the lengths of the portions of said threads intermediate their respective openings in said disk and said delivery point and the tensions of said threads are always substantially equal upon rotation of said disk within said housing.

References Cited in the file of this patent UNITED STATES PATENTS Allenson Mar. 8, 1955 2,710,631 Flammand June 14, 1955 

